Refiners subject low value hydrocarbons such as residual hydrocarbon streams to hydrodesulfurization to produce heavy hydrocarbonaceous compounds having a reduced concentration of sulfur. Residual hydrocarbons contain the heaviest components in a crude oil and a significant portion is non-distillable such as asphaltenes which are high molecular weight hydrocarbons. Residual hydrocarbon streams are the remainder after the distillate hydrocarbons have been removed or fractionated from a crude oil. A majority of the residual feedstock boils at a temperature greater than about 565° C. (1050° F.). During the desulfurization of residual hydrocarbon feedstocks, a certain amount of distillate hydrocarbons are produced including diesel boiling range hydrocarbons. However, the diesel boiling range hydrocarbons thereby produced typically fail to qualify as low sulfur diesel because of their relatively high sulfur concentration. Although a wide variety of process flow schemes, operating conditions and catalysts have been used in commercial activities, there is always a demand for new hydroprocessing methods which provide lower costs, more valuable product yields and improved operability.